The Left has traditionally assumed that human nature is so malleable, so perfectible, that it can be shaped in almost any direction. By contrast, a Darwinian science of human nature supports traditionalist conservatives and classical liberals in their realist view of human imperfectibility, and in their commitment to ordered liberty as rooted in natural desires, cultural traditions, and prudential judgments.

Sunday, May 13, 2012

Darwinian Natural Right in E. O. Wilson's New Book

Sometime in 1998, I was working in my home basement office, and I heard a telephone ringing. After my son answered the phone, he yelled into the basement: "Some guy wants to talk to you. He says he's Ed Wilson at Harvard." I picked up the phone, and we talked for about thirty minutes. He was calling from his home in Lexington, Massachusetts. We talked until his wife pulled him away from the phone.

He had read my review of his new book--Consilience: The Unity of Knowledge--and he wanted to talk about it. Although I generally agreed with most of the arguments in his book, I suggested that there was a conflict between his pursuit of a strong reductionism and his recognition of emergent phenomena that cannot be explained in a reductionistic way. He tried to persuade me that strong reductionism was the ultimate goal of science, while I argued that emergent complexity could never be fully explained in reductionistic terms.

I was reminded of that telephone conversation as I read Wilson's new book--The Social Conquest of the Earth. In 1998, my Darwinian Natural Right: The Biological Ethics of Human Nature had just been published, and much of my reasoning for Darwinian natural right in that book was shaped by Wilson's writing. Now, as I read his new book, I see again how much of my thinking has been influenced by his work, although I also see a few points of disagreement.

In this new book, I see seven major themes related to Darwinian natural right: (1) consilience, (2) emergence, (3) genetic plasticity, (4) the two peaks of social evolution, (5) the iron rule of moral evolution, (6) religion and science, and (7) the rejection of kin selection theory.

(1) ConsilienceWilson organizes his book around the questions asked in Paul Gauguin's most famous painting of human figures set in a Tahitian landscape, which apparently depicts the stages of the human life cycle from birth to death, and which includes in one corner three questions: Where do we come from? What are we? Where are we going?

To answer these fundamental questions about our human place in the natural history of the universe, Wilson suggests, we need what he has called "consilience"--the unification of all knowledge, which would draw from the natural sciences, the social sciences, and the humanities. Traditionally, we have looked to religion, philosophy, or the creative arts to answer these great questions. But Wilson argues that these three ways to understand the human condition have failed. This leaves science--in its quest for unified knowledge--as the only way to understand the human story (1, 7-10).

I think Wilson is mistaken here in his claim that philosophy and science must be separated, because of his assumption that philosophy relies purely on introspection and logic without any of the empirical research that is done by scientists. His mistake here is in turning away from what he said in Consilience, where he recognized that the search for consilience--based on the assumption that "the world is orderly and can be explained by a small number of natural laws"--began in Greek antiquity with Thales of Miletus and Aristotle (4-5). Until recently, there was no separation between philosophy and science, and what we call "natural science" today was previously called "natural philosophy." Aristotle was particularly important as a biologist who saw moral and political philosophy as a biological science. Moreover, Wilson acknowledged this in Consilience, when he identified his biological science of ethics and politics as belonging in the empiricist tradition of Aristotle, Hume, and Darwin, as opposed to the transcendentalist tradition of Plato, Kant, and Rawls (248-49, 315). (At this point, Wilson seemed to have been influenced by an article of mine published in 1995 in the American Political Science Review: "The New Darwinian Naturalism in Political Theory.")

If Wilson's project for a Darwinian unification of knowledge is to succeed, it must revive that Aristotelian tradition of natural philosophy that includes Thomas Aquinas, David Hume, and Adam Smith. Darwin understood himself as part of that intellectual tradition, particularly in adopting ideas from Hume and Smith about the natural moral sentiments. Recently, evolutionary moral psychologists like Jonathan Haidt have recognized that they are reviving the empiricist moral philosophy of Aristotle and Hume, and some contemporary philosophers like Shaun Nichols have embraced "experimental philosophy" as a way of putting their ideas to the test of empirical scientific research. Political scientists like Peter Hatemi, James Fowler, Christopher Dawes, and Rebecca Hannagan who are developing biological theories of political behavior fit into this Aristotelian and Darwinian tradition. My argument for Darwinian natural right belongs to this same intellectual project.

(2) EmergenceIn our telephone conversation in 1998, I disagreed with Wilson's statement in Consilience about reducing all knowledge to physics: "all tangible phenomena, from the birth of stars to the working of social institutions, are based on material processes that are ultimately reducible, however long and tortuous the sequences, to the laws of physics" (266). I pointed out that in most of his book, he actually rejected "physics envy" and insisted that biologists must "invariably encounter emergence, the appearance of complex phenomena not predictable from the basic elements and processes alone" (86). Later, in my chapter on emergence in Darwinian Conservatism, I defended the idea of emergent complexity--including the emergence of the mind in the brain--as superior to strong reductionism.

I am pleased to see, therefore, that in The Social Conquest of Earth, Wilson never argues for reducing everything to the laws of physics, and he implicitly endorses the idea of irreducibly emergent traits of life (see, e.g., 185, 287).

(3) Genetic plasticityOne ground for emergent complexity in Wilson's science is genetic plasticity. One odd feature of the debate that Wilson has provoked ever since the publication of his Sociobiology in 1975 is that his most fervent critics accuse him of genetic determinism, even though he has repeatedly affirmed the idea of genetic plasticity as allowing for individual and cultural variation. He repeats that idea in Social Conquest in explaining his understanding of gene-culture coevolution: the observable human variation in both individual and cultural traits does not show that such traits are free from genetic influence, because there can be great plasticity in the expression of genes that allows for a wide but still constrained flexibility in response to the cultural and individual contingencies of life (236-40).

This fits with my conception of Darwinian natural right, in which the twenty natural desires can be understood as genetic inclinations that constrain but do not determine cultural traditions and individual judgments.

One of those twenty natural desires is the desire for speech. Wilson's emphasis on genetic plasticity is manifest in his decision in Social Conquest to reverse his previous acceptance of Noam Chomsky's argument for a universal grammar as innate in human nature (231-35). In a famous debate between B. F. Skinner and Chomsky, Skinner argued that language is all learned and not at all innate, while Chomsky argued that language was too complex for children to learn as quickly and easily as they do. According to Chomsky, children must have an innately constituted deep grammar that is universal to all human beings and thus universally expressed in every human language.

In Wilson's earlier writings, he supported Chomsky's position. But now he thinks the truth is somewhere between Chomsky and Skinner: there is some uniquely human instinctive propensity to learn language--some epigenetic rules for "prepared learning" of language--but these instinctive rules are so broad that both syntax and semantics are determined by cultural learning. Following Michael Tomasello, Wilson concludes now that language is not basic, but derived, in that it arises from uniquely human abilities to read and share intentions with other people. Our natural social instincts and our cognitive capacities for social interaction and communication prepare us to learn language as a cultural tool.

Daniel Everett has made a similar argument in Language: The Cultural Tool (2012).And he sees this argument as taking the side of Aristotle against Plato. While Plato thought that meaning was ultimately derived from some transcendent realm that had to be instilled in the mind at birth, Aristotle saw meaning as learned from cultural experience of the world by social animals naturally inclined to social life. We are naturally inclined to learn language, Aristotle saw, but the meaning of words and sentences is by convention (On Interpretation, 16a1-17a17).

(4) The Two Peaks of Social EvolutionIn Sociobiology (1975), Wilson identified "Four Pinnacles of Social Evolution" (Chapter 18). These four pinnacles were the colonial invertebrates (such as the corals, the Portuguese man-of-war, and sponges), the eusocial insects (ants, bees, wasps, and termites), nonhuman mammals, and humans. Although this sequence seems to move from more primitive to more complex forms of life, it also moves from more cohesive or cooperative societies to more discordant or competitive societies. Colonial invertebrates can be seen as "perfect societies," because colonies consist of genetically identical individuals, and consequently they show absolutely altruistic cooperation. But with sexually reproducing organisms, no two individuals are genetically identical, which creates conflicts of interest even among related individuals (314, 379).

In Social Conquest, Wilson moves from four pinnacles of social evolution to two. He identifies two paths to the social conquest of the earth--the insect path and the human path. The social insects rule the invertebrate land environment. Humans rule the vertebrate land environment. Like the social insects, humans are "eusocial" in the technical sense that multiple generations of individuals live together, caring for dependent offspring and cooperating in a social division of labor. While the social insects organize their colonies largely through pure instinct, with the insect queen producing robotic offspring guided by instinct, humans must organize the cooperation of individuals through personal relationships based on social intelligence, which requires navigating through a tense social network balanced between the selfish interests of individuals and the social interests of groups. Wilson explains this tense balance in human social life between selfishness and sociality as a product of the countervailing evolutionary forces of individual selection and group selection.

Although Aristotle did not have an evolutionary theory of social cooperation, he did explain human politics by comparison with the social life of other political animals. He recognized the social insects--particularly, ants, bees, and wasps--as political animals. He also recognized that human beings were the most political animals, because their cooperation was based on language and intelligence in negotiating the complex conflicts and confluences of interests in human societies. He also saw that Plato's perfect city in the Republic was more suitable for social insects than for human beings, because human beings were moved by a love of their own that drove them into factional conflict.

(5) The Iron Rule of Moral EvolutionThe tense balance between the individual and the group in human societies constitutes what Wilson identifies as the "iron rule" of social and moral evolution: "Selfish individuals beat altruistic individuals, while groups of altruists beat groups of selfish individuals. The victory can never be complete; the balance of selection pressures cannot move to either extreme. If individual selection were to dominate, societies would dissolve. If group selection were to dominate, human groups would come to resemble ant colonies" (243). So if we ask whether human beings are innately good or innately evil, we should answer that they are both. And for that reason, "human beings and their social orders are intrinsically imperfectible" (241). Here is the scientific basis for the tragic realism of evolutionary ethics.

This evolved imperfectibility of human nature has been a major theme of my argument for Darwinian natural right, and for traditionalist conservatism and classical liberalism as conforming best to our imperfectible nature as both selfish and social animals.

The theory of multilevel natural selection--with individual selection at one level and group selection at another--explains the ultimate causes of those complex conflicts in human moral and political life that are expressed proximately in our moral emotions. Those moral emotions are well-studied in Adam Smith's Theory of Moral Sentiments, which begins by observing:

How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it except the pleasure of seeing it. Of this kind is pity or compassion, the emotion we feel for the misery of others, when we either see it, or are made to conceive it in a very lively manner. That we often derive sorrow from the sorrow of others, is a matter of fact too obvious to require any instances to prove it; for this sentiment, like all the other original passions of human nature, is by no means confined to the virtuous and humane, though they perhaps may feel it with the most exquisite sensibility. The greatest ruffian, the most hardened violator of the laws of society, is not altogether without it.

In The Descent of Man, Darwincited this opening chapter of Smith's book in developing his evolutionary theory of the moral sense as rooted in social instincts, reason, language, sympathy, and group selection.

And yet even Darwin's friend Thomas Huxley eventually rejected Darwin's evolutionary account of morality, because Huxley insisted that morality transcends nature as being a purely cultural product constituting "an artificial world within the cosmos."

More recently, some of the leading proponents of evolutionary psychology have followed Huxley in assuming that human morality belongs to a transcendent realm of cultural artifice and free will that is beyond the natural realm of causal forces open to scientific study. So when Wilson spoke about his evolutionary theory of morality in his keynote address in 1996 at the annual meeting of the Human Behavior and Evolution Society, many of the people at the convention were shocked, and they criticized Wilson for committing the "naturalistic fallacy."

In recent years, however, the rapidly accumulating research on the biological bases of morality has become so impressive that some evolutionary psychologists have begun to concede that Darwin was right, and Huxley was wrong. They have thus joined Wilson in reviving the tradition of the empirical study of morality that includes Aristotle, Hume, and Smith. My conception of Darwinian natural right falls into that tradition.

Darwinian natural right also includes that sense of honor that Wilson identifies as crucial for moral evolution, citing Kwame Anthony Appiah's The Honor Code: How Moral Revolutions Happen (2010). This sense of honor includes the moral emotions of indignation and resentment in response to injustice. This sense of injustice expresses what Leo Strauss calls "those simple experiences regarding right and wrong which are at the bottom of the philosophic contention that there is a natural right" (NRH, x, 31-32, 105); and it is this that allows us to derive "rights from wrongs" (in Alan Dershowitz's phrase): our moral history is a history of resistance to injustice from which we derive standards of fair treatment. My chapter on slavery in Darwinian Natural Right is an extended case study of this natural moral sense expressed as honorable resistance to injustice.

(6) Religion and ScienceIn my understanding of Darwinian natural right, religion satisfies the natural desire for religious understanding, and science satisfies the natural desire for intellectual understanding. In answering questions of ultimate explanation, we must appeal to some unexplained ground of all explanation. Science might appeal to nature. Religion might appeal to nature's God. In the debate between these two alternatives, neither side can refute the other.

In some of his earlier writings, Wilson has been ambiguous as to whether science and religion can coexist, or whether science must prevail over religion. In Social Conquest, he explains religion as a product of evolutionary group selection in which religion expresses tribalism, because religion reinforces the demands of the group for the loyal obedience of individuals. But then we must ask, to whom is that obedience directed? Wilson answers: "Yes, perhaps it really is to God. But perhaps it is to no more than a tribe united by a creation myth" (267). That "perhaps" suggests that there might be no final resolution of the reason/revelation debate, as I argue. But Wilson makes it clear that he foresees a future of complete secularization in which science replaces religion. He concludes his book with a profession of "blind faith" in scientific enlightenment (297), which has been a theme of his writing going back to On Human Nature (1979).

(7) The Rejection of Kin Selection TheoryFor his colleagues in evolutionary biology, the most controversial part of Wilson's new book is his rejection of kin selection theory. On this point, he draws from an article published in Nature in 2010, which he coauthored with Martin Nowak and Corina Tarnita. Their attack on kin-selection theory in that article was so controversial that it provoked criticisms from hundreds of scientists in a series of articles published in Nature in 2011.

William Hamilton developed the theory of kin selection in 1964. The idea is that animals have evolved to serve not only their personal fitness (the number of surviving offspring) but also their inclusive fitness (which includes the fitness of their collateral relatives). Hamilton put his theory into a formula: rb>c. A gene for altruism will increase in frequency in a population when the benefit (b) to the individual receiving the benefit times the degree of relatedness (r) to the altruistic individual is greater than the cost (c) to the altruist.

Part of the appeal of this theory is that it seemed to solve what Darwin recognized as a big problem for his theory of evolution: if animals have evolved for reproductive fitness, then why so some social insects have non-reproductive workers who care for the queen's offspring while producing none of their own? Hamilton's answer was that because of the reproductive system of haplodiploidy among these insects (ants, bees, and wasps), sisters are more closely related to one another than to their own offspring, and thus it serves the inclusive fitness of the sisters to rear the queen's daughters rather than reproduce their own offspring. (This explanation does not apply to termites, whose reproduction is diploid, and thus the relatedness of parents to offspring is the same as that between siblings.)

In The Insect Societies (1971) and Sociobiology (1975), Wilson defended Hamilton's kin-selection theory, which subsequently became a generally accepted theory in evolutionary biology for explaining social evolution. But now, in Social Conquest, Wilson restates the argument against kin-selection made in his article coauthored with Nowak and Tarnita: as long as multilevel natural selection (individual or group selection, or both) works generally to explain social evolution, there is no need for a theory of kin selection. (See Nowak, Tarnita, Wilson, in Nature, 466: 1057-62, 2010.)

I am not persuaded by this. But I must admit that this debate is so hard to follow that I am never sure that I understand exactly what's at issue here. The hundreds of scientists who have come to the defense of kin selection theory have surveyed the evidence that this theory has been remarkably fruitful. In responding to these critics, Nowak, Tarnita, and Wilson wrote a brief article (one and a half pages) that does not answer all the points made by the critics. (See Nature, March 24, 2011, vol. 471, pp. E1-E10.) I agree with those critics (like Samir Okasha, in Nature, October 7, 2010) who argue that multilevel selection theory is not an alternative to kin selection theory; rather, they are complementary to one another.

Indeed, Martin Nowak seems to concede this point in his recent book SuperCooperators. "Despite its limitations," Nowak writes, "Hamilton's rule has been a valuable heuristic." "Kin selection is still a mechanism for the evolution of cooperation, as long as it is properly defined" (110). Moreover, Nowak indicates that there are at least five mechanisms for the evolution of cooperation: direct reciprocity (tit for tat), indirect reciprocity (reputation), spatial selection (the structure of a population so that some individuals interact with each other more often than others), multilevel selection (individual selection and group selection), and kin selection. He thinks that indirect reciprocity is most important.

It is clear that kin selection cannot be the whole story, because we need to explain how unrelated individuals can cooperate. But it is also clear that kin selection must be part of the story, because we need to explain the tendency for individuals to be more cooperative with close relatives than with distant relatives or strangers.

The fundamental idea here was developed by Aristotle: the natural sociality of animals originates as an extension of parental care and affiliation to ever wider groups. A similar point is made by Wilson in stressing the importance for social evolution of having a nest or campsite that is defended from enemies.

All of these mechanisms for social cooperation are manifest in my list of twenty natural desires, which includes the desires for sexual mating, parental care, familial bonding, friendship, social status, justice as reciprocity, political rule, and war.

8 comments:

Anonymous
said...

In the section on the Iron Rule of Moral Evolution, you point to how Wilson's views uphold your notion of the tragic realism of evolutionary ethics. Yet, it seems that you would have to admit that as we move up the ladder of cultural evolution it appears that some arrangements have lead toward greater non-zero-sum relations understood in a positive sense. To what degree do you find that your notion of the tragic realism of evolutionary ethics agrees or disagrees with the progressive realism that Wright puts forth in his NY Times article (http://www.nonzero.org/nytprogressiverealism.htm)? Or rather how does your notion of tragic realism square with your notion of optimist realism? Is tragic realism redundant? Does it not completely capture our evolutionary history? Might progressive realism or optimist realism better capture our history? In fact, the epigraph of Wright's book, taken from Darwin's Descent of Man, suggests that Darwin himself is more of a progressive realist in terms of what to expect in the future for our species.

And lastly, isn't group selection Darwin's main theory for our moral evolution? Consider Chapter 2 in the Conclusion section of The Descent of Man, where Darwin say, "With the higher social animals, I am not aware that any structure has been modified solely for the good of the community, though some are of secondary service to it....In regard to certain mental powers the case, as we shall see in the fifth chapter [which is on intellectual and moral faculties], is wholly different; for these faculties have been chiefly, or even exclusively, gained for the benefit of the community, and the individuals thereof, have at the same time gained an advantage indirectly." I haven't read Wilson's new book, but it appears from what you've summarized that this is Wilson's "new" view, which as we see is "old". Wilson perhaps shows what has always been the problem with a Neo-Darwinian synthesis regarding the topic of "man". In fact, I think it is a good time to reassess the soundness of the Neo-Darwinian synthesis that seems to be overly preoccupied with the genes and thus misunderstands the emergent complexity that is called human behavior.

"We are naturally inclined to learn language, Aristotle saw, but the meaning of words and sentences is by convention."I'd opt for Millikan's take where meaning is determinate, and not conventional, and conventions are coordinations for cooperation. See her "Language Conventions made Simple."

Does he at all defend "natural rights" in his new book? Consilience is an argument against natural rights, since he holds self-evident truths to be an example of ethical transcendentalism, and thus they are falsehoods from his ethical empiricist point of view.

Ever since I read "Evolution of direct reciprocity under uncertainty can explain human generosity in one-shot encounters" by Delton, Krasnow, Cosmides, and Tooby, my inclination has been to wonder if it wouldn't be more appropriate to draw the distinction between selection for genes that promote long term thinking and genes that don't.